1. and 2. Depots hardly run out of fuel. Some arbp buses do go
to bbdep for refuelling before going back to arbp, for example the
N shift which 409 used to have, however, this is believed to be due
to the fuel booth being closed at 3+am.
3. Some depots do practise that, however, still a small
factor.
Main reasons are actually, advertising contracts, fleet
standardization and having to balance the mileage of buses of the
same age (warranty issue/sale of buses made easier cos normally
buyers won't want to buy high mileage buses at the same price).
